The use of gypsum-impregnated bandages as a stiffening dressing material is known. Such gypsum dressings are undesirably heavy, have a low permeability to air, rapidly lose their strength in the moist state, for example by the action of water on the hardened dressing, impede diagnostic evaluation of X-ray photographs because they absorb and scatter X-rays, and frequently give rise to skin irritation, caused by bacterial or fungal growth in the dressing, because of their retention of water.
Supporting dressings of a synthetic material, in which a textile carrier material or a carrier material based on glass fibres is coated with a polymer, for example a polyurethane which hardens in the presence of water, are also known (Chemical Orthopaedices and Related Research 103, 109-117 (1974), DE-OS (German Published Specification) No. 2,357,931 and U.S. Pat. Nos. 4 4,376,438, 4,411,262, 4,502,479 and 4,570,622). The supporting dressings based on synthetic material can be modelled to lesser degree than can gypsum dressings.